MASTIGOPHORA 



33 



Key to the genera of Astasiidae here described: 



! Body very flexible 1. ASTASIA 



a, Body rigid, sickle-shaped 2. MENOIDIUM 



1. ASTASIA Ehrenberg. Body spindle-shaped; very 

 plastic, with striped cuticula: 2 species; in fresh and salt 

 water. 



A. contorta Dujardin (Fig. 38). Length .06 mm.: 

 in decaying vegetation. 



2. MENOIDIUM Perty. Body elongate and more or 

 less bent, and rigid; cuticular stripes longitudinal: 1 

 species. 



M. pellucidum Perty. Length .08 mm.: in fresh 

 water. 



FAMILY 3. PERANEMIDAE. 



Fig. 38 



Astasia 

 contorta 

 (Calkins). 



Body usually cylindrical or ovate, plastic or rigid, 

 and covered by a striped cuticula; 1 or 2 flagella present, at the 

 base of which is a distinct mouth; no chlorophyll present: 14 

 genera. 



Key to the genera of Peranemidae here described : 



o x Body plastic. 

 6 X Body elongate, attenuated forward ........................ 1. PEBANEMA 



&, Body bottle-shaped ...................................... 2. UBCEOLUS 



o 2 Body rigid ; two flagella. 

 &! Pharynx not deep ...................................... 3. ANISONEMA 



6 a Pharynx very deep .................................... 4. ENTOSIPHON 



1. PEEANEMA Dujardin. Body tapers from behind 

 forward and very plastic, with a spirally striated cuticula 

 and a single flagellum, the tip of which vibrates when the 

 animal moves: 1 species. 



P. trichophonim (Ehrenberg) (Fig. 39). Length .08 

 mm.: in fresh water. 



2. URCEOLTJS Mereschkowski. Body spherical or ovate 

 with a neck from which the flagellum emerges : 



1 species. 



U. cyclostomus (Stein). Length .03 mm.: 

 in fresh water. 



3. ANISONEMA Dujardin. Body ovate and 

 compressed with striated cuticula and a 

 laieT&l g^,^. 2 flagella, 1 of which trails 

 behind: 3 species; in fresh and salt water. 



A. vitreum Duj. Body transparent and with longitudinal furrows; 

 length .05 mm. 



Fig. 39 

 Peranema 





Fig. 40 



Entosiphon 

 sulcatum 

 (Conn). 



